This is the final report of this project that provides a monitor of tissue blood flow by analysis of the spectrum of Doppler scattered laser light. The NIH laser Doppler Blood Flow Monitor has been tested clinically as a non-invasive monitor for skin and muscle tissue capillary blood flow. A commercial version of the instrument has been evaluated and found equivalent in performance. Further work on the applications of this system will be carried on by Dr. Bonner and associates at BEIB-NIH.